Glossary of Technical Terms

A parent radioactive atom decays into a daughter
atom in
various ways, one of which is by the emission of an alpha particle
from the parent atom's nucleus. Numerous types of radioactive
atoms occur in nature, but only three are the initiators of a decay
series: uranium-238 (238U); uranium-235 (235 U);
and thorium-232 (232Th).

(The numerical superscript signifies how heavy the element is.
Isotopes of the same element have different weights but nearly
identical chemical behavior—as for example (238U) and (235U). An
alpha particle has a weight of 4.)

Each of the three decay-series initiators decays, by a chain of
steps, into lead. For example, the alpha-decay steps in the 238U
series are the following (steps not involving alpha-decay are not
shown here):

238U

→

234Th

232Rn

→

218Po

234U

→

230Th

218Po

→

214Pb

230Th

→

226Ra

214Po

→

210Pb

226Ra

→

222Rn

210Po

→

206Pb

Similarly, 235U decays by a different series of steps to 207Pb,
and 232Th decays to 208Pb. Note that while all the series end up
with lead, each one results in a different isotope of lead.

The half-life of a given type of radioactive atom is the time
during which half the atoms in any collection will decay. The half-life
of 238U is 4½ billion years. Half-life, decay rate, and decay
constant are closely related quantities. If we assume that the
decay rate has not changed over geologic time,* and if we
measure 1) how much of a parent in a rock has decayed into its
daughter; and 2) the current rate of this decay, then we can, it is
generally believed, assess the date when the parent was
incorporated into the rock—that is, the date when the rock was
formed. In the case of Earth's oldest rocks, this date (some 3½
billion years ago) is thought to be the time when the molten Earth
first cooled down sufficiently for rocks to solidify from the
primordial magma.

*Numerous other assumptions and technicalities also come into
play.

[This review is based upon a series of telephone interviews with
Robert V. Gentry, as well as the available technical literature.]

Current physical laws may not have governed the past.

Earth's primordial crustal rocks, rather than cooling and solidifying over millions or billions of years, crystallized almost instantaneously.

Some geological formations thought to be one hundred million years old are in reality only several thousand years old.

Grant these propositions and—any researcher will tell you—the
entire structure of the historical natural sciences would dissolve into
formlessness. Few certainties would remain. Yet these very
possibilities (and others equally disintegrative) have been suggested in a
remarkable series of papers published over the past several years in the
world's foremost scientific journals—Nature, Science, and Annual
Review of Nuclear Science, among others. Nor has this assault upon
orthodoxy elicited a vigorous counterattack: the research results published
to date have been so cautiously and capably elaborated, and
evidence so thoroughly piled upon evidence, as to forestall any outcry
by those whose scientific sensibility may have been outraged. While
some investigators appear finally to be arming themselves for combat,
the issue has not yet been joined.

It was over a decade ago that Robert V. Gentry, puzzling over
questions about the Earth's age, directed his attention to an obscure and
neglected class of minute discolorations in certain minerals. He has since
examined more than 100,000 of these "radiohalos," and without doubt
stands as the world's leading authority on the subject. As an assistant
professor of physics at Columbia Union College (Takoma Park,
Maryland), he has brought to bear upon the halos an array of sophisticated
instrumentation such as few researchers ever have the privilege to
wield. As a result, he has converted the entire field of radiohalo research
into an exact science, transmuting the microscopic spheres of mystery
into rich mines of exciting and challenging information.

RADIOACTIVE HALO (or RADIOHALO): "In some thin samples of
certain minerals, notably mica, there can be observed tiny aureoles of
discoloration which, on microscopic examination, prove to be concentric
dark and light circles with diameters between about 10 and 40μm
[a lone micrometer is one-millionth of a meter] and centered on a tiny
inclusion. The origin of these halos (first reported between 1880 and
1890) was a mystery until the discovery of radioactivity and its
powers of coloration; in 1907 Joly and Mugge independently suggested
that the central inclusion was radioactive and that the alpha-emissions
from it produced the concentric shells of coloration. . . . halos command
attention because they are an integral record of radioactive decay in
minerals that constitute the most ancient rocks" (1).

Gentry's studies have led him to the following conclusions:

Some halos ("polonium" halos) imply a nearly instantaneous
crystallization of Earth's primordial rocks: and this crystallization
must have occurred simultaneously with the synthesis/creation of
certain elements.

Some halos correspond to types of radioactivity which are
unknown today.

Whereas radiohalos have been thought to afford the strongest
evidence for unchanging radioactive decay rates [p. 235] throughout geological
time (and these rates enable scientists to determine rock ages), in
actuality the overall evidence from halos requires us to question the
entire radioactive dating procedure: something appears to have
disrupted the radioactive clocks in the past.

Halos in coal-bearing formations that are conventionally
thought to be 100 to 200 million years old suggest these strata to be
only several thousand years old. Further, the time required for coal
formation is much less than previously thought.

Taken together, these conclusions point to one or more great
"singularities" in Earth's past—events or processes that are
discontinuous with the rest of history, unique occurrences that
critically affect the data we now have. If we attempt to interpret
these data solely in terms of current processes, we go astray.

In this report we will discuss only those researches leading to
conclusion (1), reserving the rest for a subsequent report.